آب و فاضلاب (Jul 2020)
Optimization of Intermittent Water Supply Systems Using Particle Swarm Optimization Algorithm and Pressure Driven Hydraulic Analysis
Abstract
In this research, intermittent water supply is optimized using pressure driven hydraulic analysis and particle swarm optimization algorithm with the aim of maximizing the uniformity of water distribution in the network and reliability. In the following, by calculating the resiliency as an efficiency criterion, system performance is evaluated. Obtained results from pressure driven hydraulic analysis and demand driven hydraulic analysis are compared. In this regard, the particle swarm optimization algorithm and the EPANET hydraulic analysis model are linked. Pressure driven hydraulic analysis is performed by applying some modifications on the hydraulic calculation process. The proposed model is evaluated on a sample network in several water shortage scenarios. According to the obtained results, the objective function (uniformity of water distribution) has higher values for the scenarios with lower water shortage, so that the maximum value is relevant to the scenario without water shortage. The values of the objective function for scenarios with pressure driven hydraulic analysis are 20% more than its values for scenarios with demand driven hydraulic analysis. By comparing the values obtained for system efficiency criteria it can be observed that the network resiliency and nodal resiliency for most of the scenarios with demand driven hydraulic analysis are more than their values for scenarios with pressure driven hydraulic analysis. This is because of the independency of nodal discharge from nodal pressure in demand driven hydraulic analysis that leads to unreal values for nodal discharges and therefore, hydraulic failure accrues rarely. The maximum value achieved for resiliency is around 99% which is relevant to efficiency threshold of 70% in nodal form. Uniformity and equity of water distribution between demand nodes and as a result satisfaction of stakeholders can be maximized by using optimization models. Employing pressure driven hydraulic analysis models makes it possible to simulate the behavior of water distribution networks realistically.
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